Polyoxyalkylenes containing alkaline catalyst residues chelated with benzoic acid derivatives

ABSTRACT

The oxidation promoting harmful effects of the presence of an alkaline catalyst in a polyoxyalkylene can be eliminated and the product made more resistant to oxidation especially at elevated temperatures by the incorporation therein of soluble salts of certain benzoic acid derivatives. The soluble salts can be formed by reaction with the alkali or alkaline earth metal ion derived from the alkaline catalyst utilized in the polymerization of the polyoxyalkylene.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to polyoxyalkylenes made by polymerizing at leastone alkylene oxide in the presence of an initiator and a basic catalyst.

2. Description of the Prior Art

Login in U.S. Pat. No. 4,118,326 discloses that a polyoxyalkylene can beneutralized with a saturated carboxylic acid containing up to 18 carbonatoms subsequent to polymerization of alkylene oxides with an activehydrogen-containing initiator in the presence of an alkaline catalystsuch as potassium hydroxide. Instead of removing the alkaline catalystresidue remaining subsequent to polymerization of the polyoxyalkylene,formation of the salt with the above saturated carboxylic acid providesimproved oxidation stability when the polyoxyalkylene is utilized as aspin-finish lubricant for processing synthetic fibers.

Newkirk et al in U.S. Pat. No. 4,110,227 disclose lubricants forsynthetic fibers such as polyester and nylon which are oxidation-stablepolyoxyalkylene compounds. The polyoxyalkylenes are initiated utilzing adifunctional phenol as an active hydrogen-containing compound. Thepresence of the phenolic initiator compound residue in the chain of thepolyoxyalkylene provides improved heat stable polyoxyalkylenelubricants.

Brenkman et al in U.S. Pat. No. 3,365,402 disclose a process foreliminating the harmful effects of an alkaline catalyst in acapillary-active product (polyoxyalkylene). Catalyst ions remainingafter the polymerization of the polyoxyalkylene are neutralized with alaurylpolyoxyethylene acetic acid. Such a product is chosen so as toprovide compatibility with the polyoxyalkylene main product and so asnot to impair the properties of the main product.

Mago in U.S. Pat. No. 4,263,167 discloses that an effective amount ofthe sodium salt of salicylic acid is a good oxidation inhibitor forpoly(alkylene oxide) present at 10 percent aqueous concentration whenexposed to a temperature of 70° C. for 8 days but was not a goodcorrosion inhibitor for steel. Methylene or sulfur-bridgedhydroxyl-substituted aromatic carboxylic acids are both oxidationinhibitors for poly(alkylene oxides) and good corrosion inhibitors forsteel.

It has been the practice generally to neutralize the residue of thealkaline catalyst utilized in the preparation of polyoxyalkylenes.Inorganic acids have been added so as to form soluble salts ofprecipitates which are subsequently filtered out so as to remove alkalior alkaline earth metal ions. In those cases where the inorganic acidutilized forms soluble salts with the alkaline catalyst, for instancepotassium phosphate, it has been found possible to utilize theneutralized polyols in the preparation of certain types ofpolyurethanes. Alternatively, the prior art use of adsorbents such asmagnesium silicate in the presence of water followed by filtrationprovides a means of removal of the metal ions derived from the alkalinecatalyst. It remains to this date industry practice to remove the metalion residue of the alkaline catalyst from a polyoxyalkylene to theextent that no more than about 5 ppm of alkali or alkaline earth metalion remains.

Common approaches to the removal of the alkaline catalyst have beenadsorption on magnesium silicate or the neutralization of the alkalinecatalyst with an inorganic acid which forms a precipitate and thesubsequent removal of the precipitate or the magnesium silicate byfiltration. Various other means of removal of the alkaline catalyst havebeen proposed such as dilution of the polyoxyalkylene with a waterinsoluble solvent and the subsequent washing of the solvent solutionwith water. Another approach has been the use of ion exchange columnsfor the removal of catalyst from low viscosity polyoxyalkylenes. Afurther approach is the neutralization of the alkaline catalyst withcarbon dioxide, and the subsequent removal of water under reducedpressure with the subsequent removal of the alkali carbonate formed byfiltration.

SUMMARY OF THE INVENTION

The use of certain benzoic acid derivatives which form soluble saltswith certain metal ions to neutralize the alkaline catalyst remainingsubsequent to the polymerization of a polyoxyalkylene provides a meansof improving the oxidation stability of a polyoxyalkylene or mixturethereof. Such improved oxidation stable polyoxyalkylenes are usefulparticularly as lubricants for synthetic fibers.

The neutralized polyoxyalkylenes also can be used in the preparation ofurethanes. The polyoxyalkylenes find use, for instance, in thepreparation of solid, non-cellular polyurethanes and in the preparationof rigid and flexible polyurethane foams.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

There are disclosed improved oxidation stable polyoxyalkylene compoundswhich are useful either alone or in admixture with prior art,oxidation-susceptible polyoxyalkylene compounds especially as lubricantsfor synthetic textile fibers or in the preparation of polyurethanes.Lubricants are required to be applied to a textile fiber subsequent tospinning to reduce the tendency towards breakage of the individualfilaments as they are subjected subsequently to various mechanicalstrains. These lubricants function to enable satisfactory handling ofsuch fibers as nylon and polyester in processing applications such asspinning, twisting, winding, reeling, drafting, weaving, carding,combing, knitting, and throwing, and are particularly suitable for usein the production of a synthetic fiber continuous filament, false twist,textured yarn, as well as other type yarns.

The improved oxidation stable polyoxyalkylene compounds of the inventionare also useful in the preparation of polyurethanes where generallyheretofore polyoxyalkylenes used to react with organic polyisocyanateswere required which are substantially free of alkaline catalystsresidues used in the preparation of the polyoxyalkylene. Thepolyoxyalkylenes of the invention containing a soluble salt which is thereaction product of the catalyst used to prepare the polyoxyalkylenewith certain derivatives of benzoic acid can be reacted to form cellularor homogeneous polyurethane products. The heretofore undesirable action,during the formation of the polyurethane, of the strongly basicinorganic catalyst utilized in the preparation of the polyoxyalkylene isovercome in accordance with the invention by neutralization with certainbenzoic acid derivatives. The alkali or alkaline earth metal ion presentwill no longer substantially catalyze side reactions such as thepolymerization of isocyanate groups thus rendering the control ofpolyurethane-forming reactions difficult. Surprisingly, the soluble saltformed by reaction with certain benzoic acid derivatives is, at most,only a mild catalyst for the isocyanate active hydrogen reaction or forthe undesirable side reactions of isocyanate group polymerization.

By neutralizing the alkaline catalyst residues present at the end of thepreparation of a polyoxyalkylene with the benzoic acid derivatives ofthe invention there is avoided the time-consuming and energy-wastefulprocesses of water-washing a water-insoluble solvent solution of thepolyoxyalkylene, adsorbing the metal ions with magnesium silicates, orforming a precipitate with an inorganic acid and filtering the magnesiumsilicate or the inorganic acid salt precipitate out of thepolyoxyalkylene. Oftentimes the higher molecular weight materialsrequire a filtration operation at elevated temperatures so as to speedthe process. To improve oxidation stability, alkali or alkaline earthmetal salts of the benzoic acid derivatives of the invention can also beadded to olyoxyalkylenes from which catalyst residues have beensubstantially removed.

According to the invention, polyoxyalkylenes having improved oxidationstability can be prepared by neutralizing the alkaline catalyst residuesremaining subsequent to polymerization with at least one of a benzoicacid derivative having the formulas: ##STR1## wherein R₁ is selectedfrom the group consisting of alkyl and alkenyl of up to 6 carbon atoms;R₂ is selected from the group consisting of hydroxyl, an alkyl etherresidue having up to 4 carbon atoms, an hydroxy alkyl ether residuehaving up to 4 carbon atoms, an alkenoxy or oxyalkanoic acid esterresidue having up to 18 carbon atoms and benzoyl; R₃ is individuallyselected from the group consisting of hydrogen, alkyl ether residueshaving up to 4 carbon atoms, hydroxy alkyl ether residues having up to 4carbon atoms, alkyl or alkenyl residues of up to 6 carbon atoms,halogen, and carboxyl groups; and X is selected from the groupconsisting of (1) carbon and (2) carbon together with nitrogen.

The novel lubricants of the invention contain alkali or alkaline earthmetal salts or mixtures thereof of the benzoic acid derivatives offormulas I and II. The proportion of these salts present in thepolyoxyalkylene compound depends upon the amount of catalyst remainingafter polymerization. The original starting proportion of the catalystcan be about 0.002 to about 10.0 percent by weight, preferably from 0.01to 5.0 percent by weight and most preferably about 0.01 to about 1.5percent by weight, all based upon the total weight of the final product.As is conventional, higher proportions of catalyst and low reactiontemperatures are used where high molecular weight polyoxyalkylenes aredesired. Conversely, where low molecular weight polyoxyalkylenes aredesired, low catalyst proportions are utilized at moderate to highpolymerization temperatures. As polymerization progresses, the catalystis diluted by the addition of alkylene oxide so that as little as 1/2 to1/10 of the original catalyst remains. Both organic and inorganiccatalysts can be used to prepare polyoxyalkylenes. Conventional organiccatalysts for the preparation of polyoxyalkylenes are alkali metalalkylates having from 1 to 4 carbon atoms in the alkyl radical, such assodium and potassium methylate, sodium and potassium ethylate, potassiumisopropylate and sodium butylate. Inorganic catalysts such as alkalimetal hydroxides and alkaline earth metal hydroxides can be used.Preferably, alkali metal hydroxides such as sodium hydroxide and mostpreferably potassium hydroxide are used.

Representative examples of benzoic acid derivatives under formulas I andII are salicylic acid (orthohydroxybenzoic acid), ortho-hydroxycinnamicacid, 2-(parahydroxybenzoyl) benzoic acid, and acetylsalicylic acid.

The preparation of polyoxyalkylenes is otherwise in accordance withconventionally known procedures. For instance, alkylene oxides having upto 4 or with from 2 to 4 carbon atoms are generally added to initiatorcompounds in the presence of basic catalysts. Suitable alkylene oxidesinclude ethylene oxide; 1,2-propylene oxide; 1,2-butylene oxide;1,3-butylene oxide and tetrahydrofuran. Alternatively, aromaticsubstituted alkylene oxides having 2 to 4 aliphatic carbon atoms can beused, such as styrene oxide, and both aliphatic and aromatic substitutedglycidyl ethers having 2 to 4 aliphatic carbon atoms such astertiary-butyl glycidyl ether or phenyl glycidyl ether can be used.Preferably ethylene oxide, mixtures of ethylene oxide and 1,2-propyleneoxide, or 1,2-propylene oxide are utilized in the preparation of thepolyoxyalkylenes of the invention. The alkylene oxides can bepolymerized so as to form heteric or block copolymers or combinations ofheteric and block copolymers by appropriate procedures known in the art.The polyoxyalkylenes are generally reacted with an initiator compound inthe preparation thereof having one or more reactive hydrogen atoms.Illustrative of such initiator compounds are water, aliphatic mono-,di-, or polyhydric alcohols, for instance, methyl alcohol, ethylalcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol,ethylene glycol, propylene glycol, diethylene glycol, dipropyleneglycol, triethylene glycol, tripropylene glycol, glycerol, hexanetriol,pentaerythritol, sorbitol, trimethylol propane; aliphatic or aromaticmono-, di- or triamines, e.g., stearylamine, ethylenediamine,diethylenetriamine, hexamethylenediamine, phenylenediamine; aliphaticcompounds having amino and hydroxyl groups, e.g., ethanolamines,propanolamines; aliphatic compounds having a mercapto group, e.g.,dodecylmercaptan, 2,3-dimercapto-1-propanol; and aromatic compoundshaving one or more hydroxyl groups, e.g., nonyl phenol,1,1,3-tris(p-hydroxyphenyl) propane, 1,1,2,2-tetrakis(p-hydroxyphenyl)propane, and 4,4'-isopropylidenediphenol.

In detail, the polyoxyalkylenes are manufactured by reacting a mixtureof initiator compound and basic catalyst at temperatures of from 90° C.to 150° C., preferably 100° C. to 130° C., with at least one alkyleneoxide at such a rate that the alkylene oxide is taken up by the reactionmixture in approximately 2 to 30 hours, preferably about 5 to 10 hoursat atmospheric pressure, or as the case may be, under higher pressuresof about 1 to 20 atmospheres, preferably about 1 to 5 atmospherespressure. The alkylene oxide can be diluted with inert gas, for instancenitrogen and usually the alkylene oxide is added to the reaction mixtureduring the course of the reaction. Where mixed alkylene oxides arereacted, heteric polymers are produced. Successive addition of differentalkylene oxides produce block polymers. After completing thepolymerization reaction, any unreacted alkylene oxide is removed bystripping under reduced pressure and at temperatures of from 100° C. to150° C., the polyoxyalkylene is treated with the benzoic acid derivativeof the invention at temperatures of from 20° C. to 150° C., preferablyat temperatures of from 40° C. to 100° C. The reaction mixture isthereafter stirred from 0.5 to 20 hours, preferably from 1 to 5 hours,after which time the reaction vessel is vented, and volatile sideproducts are stripped off under reduced pressure at temperatures between50° C. and 150° C.

The polyoxyalkylenes of the invention are more economical to preparethan those polyoxyalkylenes of the prior art having substantially nocatalyst remaining in the polyol as the result of the substantiallycomplete removal of the alkaline catalyst ions. One reason for the priorart removal of the catalyst remaining in a polyoxyalkylene subsequent topolymerization is the fact that presence of catalyst tends to acceleratethe degradation of the polyoxyalkylene upon subsequent exposure to airand elevated temperatures. Another reason for the prior art removal ofthe catalyst residues is the effect of the catalyst upon the reaction ofan organic polyisocyanate with the polyoxyalkylene. The presence of astrongly basic inorganic catalyst is undesirable in such polymerizationssince its presence can cause undesirable side-reactions such as thepolymerization of the isocyanate groups, and since the remainingcatalyst also is a catalyst for the reaction of isocyanate groups withactive hydrogen atoms (present in the polyoxyalkylene). Thus the controlof the polyurethane-forming reaction is made more difficult.

Unexpectedly, it has been found that the benzoic acid derivative saltsof the metal ion of the alkaline catalyst used in the preparation ofpolyoxyalkylenes provide improved oxidation stability in thepolyoxyalkylenes in which it is present, and that in this salt the metalion is so firmly bound that its interference in polyurethane-formingreactions is minimal. The use of such oxidation stabilizedpolyoxyalkylenes thus overcomes the wasteful energy- and time-consumingprocesses involved in purification processes such as the filtration andremoval by adsorption of the alkaline catalyst residues from thepolyoxyalkylenes. Because of the substantial reduction in processingtime as well as energy costs related to the adsorption, washing, orfiltration steps utilized in prior art polyoxyalkylene processes, theoxidation stable polyoxyalkylenes of the invention are more economicalto manufacture as well as superior in oxidation stability to thepolyoxyalkylenes of the prior art.

Graft copolymer dispersions comprising a polyoxyalkylene and graftedvinyl polymer and their use in the preparation of polyurethanes are wellknown in the art. These are disclosed in U.S. Pat. No. 3,383,351 toStamberger, U.S. Pat. No. 3,652,639 and U.S. Re. Pat. No. 29,014 both toPizzini et al, all of which are incorporated herein by reference.Preferably the grafted vinyl polymer is derived from a mixture ofacrylonitrile and styrene which are reacted with an unsaturated polyolcontaining from 0.10 mole to 0.70 mole of unsaturation per mole ofpolyol.

The oxidation stabilizer of this invention can be employed together withknown stabilizers, e.g., butylhydroxy-anisol, dibutyl-hydroxy-toluene,2-α-alkylcycloalkyl-4,6-dimethylphenol,bis(2-hydroxy-3-α-alkylcycloalkyl-5-methylphenyl) methane, mono- ordialkyl-phenol, mono- or dialkyl biphenol, mono- or dialkyl cresol,methylenebis(alkylphenol), mono- or dialkyl hydroquinone, hydroquinone,tris(alkylbenzyl)-phenol, etc. In such a case, the effect on thestabilization of polyoxyalkylene polyol increases synergistically ingeneral.

The quantity of the soluble salt of this invention, which can exhibit astabilizing effect on the polyoxyalkylene is about 0.01-1 percent byweight relative to the polyoxyalkylene to be stabilized, preferablyabout 0.05-0.5, and most preferably about 0.01 to about 0.1 percent byweight is used. However, this value is not restrictive and any quantityof more than 1 percent of the soluble salt of this invention relative tothe polyoxyalkylene can be employed in the method of the invention withsatisfactory results. Generally the use of less than about 0.01 percentof the soluble salt of this invention is not effective in stabilizing apolyoxyalkylene or mixture thereof. When the stabilizer of thisinvention is employed together with known stabilizer(s), the quantity ofthe stabilizer of this invention may be the same as that of the addedknown stabilizer(s), or more or less than that of the added knownstabilizer(s). The total quantity of the stabilizer of this inventionand the added known stabilizer(s) can generally be about 0.05 to about 1percent preferably about 0.05 to about 0.5 percent by weight relative tothe polyoxyalkylene. In general the ratio of the amount of thestabilizer of this invention relative to that of known stabilizers isgenerally about 10 to 100 to about 100 to 100.

The addition of the benzoic acid derivative to the polyoxyalkylene canbe carried out conveniently in a variety of ways. The addition of thebenzoic acid derivative of the invention can be made in a solid state,that is by adding the acid directly to the polyoxyalkylene upon theconclusion of the polymerization process so as to neutralize thealkaline catalyst used in the preparation thereof. The benzoic acidderivative can also be added to the polyoxyalkylene as a solution inwhich it is dissolved in a suitable solvent such as a C₁ -C₄ alkylalcohol, a C₂ -C₄ alkyl ether, or an aromatic hydrocarbon such astoluene. The addition can be carried out subsequent to thepolymerization process with just enough or a slight excess of thebenzoic acid derivative of the invention being added so as to neutralizethe alkaline catalyst residue. When the benzoic acid derivative is addedto the polyoxyalkylene directly, i.e., in a solid form and not in asolution in a solvent, it is especially important to insure that thebenzoid acid derivative of the invention is mixed thoroughly into thepolyoxyalkylene to dissolve the benzoic acid derivative and to insureuniformity in the polyoxyalkylene.

Where conventional aromatic based oxidation stabilizer compounds areadded to the polyoxyalkylene together with the benzoic acid derivativeof this invention, or in a situation where two or more kinds of thebenzene derivatives of this invention are added to the polyoxyalkylene,the addition of the benzoic acid derivative is preferably carried outfirst to avoid adversely affecting aromatic-based oxidation inhibitors.Polyoxyalkylenes stabilized against oxidation utilizing at least one ofthe benzoic acid derivatives of the invention, alone or in combinationwith known stabilizers, are effectively inhibited against degradation ordecomposition of the polyoxyalkylene, as indicated by an increase in theacid value, decrease in viscosity, or other indication of degradation ordecomposition of polyoxyalkylenes well known to those skilled in theart.

Conventional polyoxyalkylenes are readily subject to degradation ordecomposition when exposed for any considerable length of time to theair or the action of ultraviolet rays, and this degradation ordecomposition is enhanced by exposure to elevated temperatures. Whenpolyoxyalkylenes are heated in air, they undergo a remarkable decreasein weight, apparently due to the formation of degradation ordecomposition products in the form of lower molecular weight compoundswhich are relatively volatile and evaporate readily into the air. Evenwhere polyoxyalkylenes are kept at room temperature in air for sometime, such as 10-20 days or longer, an aldehyde-like or dioxane-likeodor often develops. The degraded polyoxyalkylenes give a positivereaction to fuchsin-aldehyde reagent whereas the undecomposedpolyoxyalkylenes give neither an aldehyde-like odor nor a positivereaction to fuchsin-aldehyde reagent.

It is believed that the oxidation of polyoxyalkylenes is accompanied bythe formation of carbonyl compounds, peroxides and acids, and themanifestation of such deterioration is formation of color. Often, adecrease in viscosity and the formation of volatile by-products asindicated by fuming of the composition at elevated temperatures occurs.The tendency of textile lubricants to fume upon use at elevatedtemperature is commonly used as an indication of the oxidation stabilityof the lubricant. It is therefore common to evaluate the oxidationstabililty of such products by thermogravimetric analysis. In such amethod, the loss in weight after heating at elevated temperaturesprovides a clear indication of the susceptiblity of the polyoxyalkyleneto oxidation at elevated temperatures.

More specifically, the polyoxyalkylene compounds of the invention usefulas fiber lubricants are those which are either homopolymers orcopolymers having regularly repeating monomer units or segregated"blocks" of different structure in the polymer chain or hetericcopolymers. The molecular weight of such polyoxyalkylenes is about 300to about 12,500, preferably about 300 to about 2000. The weight ratio ofethylene oxide utilized in comparison with the other lower alkyleneoxides such as 1,2-propylene oxide or butylene oxide is generally about90:10 to about 10:90, preferably about 80:20 to about 20:80, and mostpreferably about 75:25 to about 50:50. It is desirable for certainembodiments of the fiber lubricant polymers of the invention to maintaina ratio of ethylene oxide to other lower alkylene oxides in order thatthe dispersibility of the lubricant in water will be suitable for thelubricating use intended. However, additional emulsifiers also can beutilized in the lubricant composition to provide suitable dispersibilityof the alkylene oxide. As is well known, a textile fiber lubricantcomposition generally is required to have excellent scourability so asto allow easy removal of the lubricant subsequent to processing of theyarn.

Generally the polyoxyalkylene lubricants are applied to the synthetictextile fiber alone or in mixtures with prior art fiber lubricants. Atleast 25 percent by weight of the mixture is the oxidation-stablepolyoxyalkylene of the invention. The lubricants are applied to thefiber at temperatures of about 25° C. to about 70° C. simply by drawingfiber through a bath of a lubricant with or without diluting water.Water dispersibility or solubility of the lubricants of the inventioncan be provided by appropriate levels of ethylene oxide utilized in thepreparation thereof. Such water dispersibility or solubility not onlypermits east of application but ease of removal of the lubricants fromfibers subsequent to processing. Under typical conditions, the amount oflubricant on the fiber, on the basis of the weight of the fiber, isgenerally an effective lubricating amount up to about 4 percent byweight, preferably about 0.5 percent to about 1.5 percent by weight, oflubricant based on the weight of the fiber. Where the lubricant isdispersible or soluble in water, the simple expedient of diluting thelubricant with water to the required concentration permits variations inthe amount of lubricant to be applied to the fiber.

The preferred polyester fibers are produced from the linearterephthalate polyesters, that is, the polyesters of a glycol containingfrom 2 to about 20 carbon atoms and a dicarboxylic acid componentcontaining at least about 75% terephthalic acid. The remainder, if any,of the dicarboxylic acid component may be any suitable dicarboxylic acidsuch as sebacic acid, adipic acid, isophthalic acid, sulfonyl4,4'-benzoic acid or 2,8-dibenzofuran dicarboxylic acid. The glycolsused can contain 2 or more carbon atoms in the chain, for instance,ethylene glycol, diethylene glycol, butylene glycol, decamethyleneglycol and bis(1,4-hydroxy methyl) cyclohexane. Examples of linear,terephthalate polyesters which can be employed include poly(ethyleneterephthalate) and poly(butylene terephthalate).

Any suitable nylon polymer which provides high tenacity yarn can beutilized in combination with the lubricants of the invention to producefalse twist or high bulk yarn. The preferred nylon fibers are thoseproduced from the following polymers: poly(hexamethylene adipamide) andpoly(caprolactam).

Utilization of the fiber lubricants of the invention can be in anyconventional spin-drawing process or in a separate drawing processavailable in the prior art. The treatment of the synthetic fibers withthe fiber lubricants of the invention can be effected by any methodpracticed in the prior art to provide lubrication. Usually, the treatingagent of the invention is applied to the fibers as an aqueous emulsionhaving a concentration of 2 to 30% by weight. Sufficient lubricity isobtained with a dry weight add-on of the treating lubricant of usuallyabout 0.05% to about 3.0%, preferably about 0.2% to about 1.0%, byweight based upon the weight of the thermoplastic, synthetic fibers. Thetemperature to which the fibers are exposed usually ranges from about150° C. to about 270° C., preferably at least about 200° C. The fiberlubricants of the invention provide especially satisfactory lubricationand resistance to oxidation upon exposure over the temperature range ofabout 200° C. to about 230° C.

In addition to their use as textile lubricants, the polyoxyalkylenesneutralized with the benzoic acid derivative of the invention are usefulas surface active agents, hydraulic fluids, and in the manufacture ofsolid, non-cellular polyurethanes and rigid, semi-rigid, and flexiblepolyurethane foams. While it is conventional to supply polyoxyalkylenesfor use in preparation of polyurethane foams and solid polyurethanes,which are substantially free of catalyst metal ion (containing up toabout 5 ppm), the oxidation stable polyoxyalkylenes of the inventionhave been found to be useful organic compounds having active hydrogenatoms, as determined by the Zerewitinoff method, for use in thepreparation of such polyurethanes as well as in the preparation ofpolyurethane prepolymers.

In the evaluation of the thermostability of the polyoxyalkylenelubricants of the invention, a so-called "Pan Test" is generallyutilized by the fiber industry. In this method, triplicate 3 gramsamples of polyoxyalkylene-containing fiber lubricants are placed in 2inch diameter aluminum weighing dishes in a circulating air oven or on ahot plate, heated to about 240° C. The weight of the polyoxyalkyleneremaining in the pan is determined periodically. At the end of the test,the color and water solubility of the remaining polyoxyalkylene, orresidue thereof, are noted. The solubility of the polyoxyalkylene at theend of the test is an important criteria for a useful fiber lubricantsince the lubricant must be washed off the texturizing equipment, onwhich it is deposited during fiber processing, at regular intervals toeliminate buildup of deposits.

Evaluation of the oxidation stabilized polyoxyalkylenes of the inventionin the preparation of polyurethanes was conducted by the preparation offree rise, flexible polyurethane foams using water as a blowing agent,rigid polyurethane foams, and rigid, non-cellular polyurethane castings.Appearance of the flexible foam, rise time, foam height and foam weightof the flexible foam prepared utilizing a graft polyol containingpotassium salicylate were compared with a similar formulation madeutilizing a polyol substantially free of catalyst residues (that is,containing less than 0.5 ppm).

The following examples illustrate the various aspects of the inventionbut are not intended to limit its scope. Where not otherwise specifiedthroughout this specification and claims, temperatures are given in °C.and parts, percentages, and proportions are by weight.

EXAMPLE 1

This example illustrates the preparation of a heteric copolymerpolyoxyalkylene fiber lubricant of the invention which is initiatedutilizing a combination of bisphenol A (4,4'-isopropylidenediphenol) anddiethylene glycol and containing ethylene oxide and propylene oxideresidues which has been neutralized with salicylic acid.

A heteric copolymer polyoxyalkylene was prepared by adding 86 grams of4,4-isopropylidenediphenol, 148 grams of diethylene glycol and 12 gramsof a 45 percent by weight aqueous solution of potassium hydroxide to 61grams of a mixture of 1 mole of 4,4'-isopropylidenediphenol and 7.6moles of propylene oxide in a clean, dry, nitrogen-filled one-gallonautoclave equipped with temperature, pressure, and vacuum controls. Themixture was heated with agitation to 125° C. and then the autoclave waspressurized and purged with nitrogen. Water and volatiles were removedby stripping at 125° C. and 10 mm of pressure. The vacuum was relievedwith nitrogen to 0.2 pounds per square inch gauge and a mixture of 1879grams of propylene oxide and 626 grams of ethylene oxide were added atthe rate of 300 to 400 grams per hour at a pressure of 9 pounds persquare inch gauge and a temperature of 125° C. When addition wascompleted, the reaction mixture was allowed to react at constantpressure for 1 to 3 hours. The reaction mixture was then cooled to 80°C., the reactor vented, and the product discharged. The polyoxyalkyleneproduct obtained was neutralized with salicylic acid to a pH of 6.7 andstripped at 450° C. and 10 mm or mercury. A clear, colorless mixture wasobtained containing the potassium salt of salicylic acid. The molecularweight of the product was 1451, as derived from hydroxyl number whichwas determined to be 77.3.

EXAMPLE 2

Example 1 was repeated adding 0.25 percent by weight, based upon theweight of the polyoxyalkylene, of a commercial antioxidant sold underthe trademark WINGSTAY L.

EXAMPLE 3 (Control--forming no part of this invention)

A polyoxyalkylene was prepared in accordance with the procedure ofExample 1 except that the residual alkaline catalyst was not neutralizedwith salicylic acid but instead was removed by adsorption on magnesiumsilicate followed by filtration to remove both the magnesium silicateand the potassium ion.

EXAMPLE 4

A heteric copolymer polyoxyalkylene was prepared as follows: There wasadded to a clean, dry autoclave equipped with temperature, pressure, andvacuum controls 3200 grams of tetradecanol and 75 grams of a 45 percentby weight aqueous solution of potassium hydroxide. The autoclave waspurged with nitrogen and pressure checked and then evacuated to lessthan 10 mm mercury while heating to 105° C. The mixture was stripped at105° C. for 1 hour and then a mixture of 8300 grams of ethylene oxideand 8300 grams of propylene oxide were added over a 9 hour period at atemperature of 125° C. The product was cooled to 80° C. and the reactordischarged. The heteric copolymer polyoxyalkylene obtained wasneutralized to a pH of 6.7 with salicylic acid to obtain a clear,colorless mixture of the potassium salt of salicylic acid and thepolyoxyalkylene.

EXAMPLE 5 (Control--forming no part of this invention)

Example 4 was repeated but instead of neutralizing with salicylic acid,the polyoxyalkylene was neutralized with benzoic acid to a pH of 6.7. Aninsoluble precipitate was formed.

EXAMPLE 6 (Control--forming no part of this invention)

The polyoxyalkylene prepared in Example 4 was neutralized with aceticacid instead of salicylic acid. An insoluble precipitate was formed.

EXAMPLE 7 (Control--forming no part of this invention)

The polyoxyalkylene prepared in Example 4 was neutralized withpara-hydroxy benzoic acid instead of salicylic acid. An insolubleprecipitate was formed.

EXAMPLE 8 (Control--forming no part of this invention)

Example 6 was repeated and there was thereafter added thereto 0.25percent by weight, based upon the weight of the polyoxyalkylene, of acommercial antioxidant sold under the trademark WINGSTAY L.

EXAMPLE 9

A block copolymer polyoxyalkylene was prepared by adding to a clean, dryautoclave equipped with temperature, pressure, and vacuum controls 600grams of diethylene glycol and 120 grams of a 45 percent aqueoussolution of potassium hydroxide. The autoclave was purged with nitrogenand pressure checked and then evacuated to less than 10 mm of mercurywhile heating to 125° C. The reactor contents were stripped for 1 hourat 125° C. and then the reactor was pressurized to 35 pounds per squareinch gauge with nitrogen. Thereafter, 4300 grams of ethylene oxide wereadded over a 1 hour period followed by 15,000 grams of propylene oxideover a 9 hour period. The product obtained was cooled to 80° C. and thereactor discharged. A 200 gram portion of the block copolymer obtainedcontaining 0.01 mole of potassium hydroxide was neutralized with 0.01mole of salicylic acid. The salicylic acid was dissolved in the productby heating the mixture to about 40° C. and stirring the mixture for 30minutes. A clear, colorless solution was obtained.

EXAMPLE 10

To a 200 gram portion of the block copolymer obtained prior toneutralization in Example 9, there was added 0.01 mole ofacetylsalicylic acid instead of the salicylic acid utilized in Example9. A clear, colorless mixture was obtained containing the potassium saltof acetylsalicylic acid and the block copolymer polyoxyalkylene.

EXAMPLE 11

To a 200 gram sample of the block copolymer polyoxyalkylene obtained inExample 9 prior to neutralization, there was added 0.01 moles ofortho-hydroxy cinnamic acid to neutralize the 0.01 mole of potassiumhydroxide present. A clear, colorless solution of the potassium salt ofortho-hydroxy cinnamic acid and the block copolymer polyoxyalkylene wasobtained.

EXAMPLE 12 (Control--forming no part of this invention)

To a 200 gram portion of the block copolymer polyoxyalkylene obtained inExample 9 (prior to neutralization with salicylic acid) there was added0.01 mole of metahydroxybenzoic acid to neutralize the 0.01 mole ofpotassium hydroxide present. An insoluble precipitate was formed.

The heat stability of certain of the neutralized polyoxyalkylenes in theabove examples was compared with the heat stability of the samepolyoxyalkylene from which potassium ion has been removed in aconventional manner utilizing magnesium silicate and filtration. Resultsare shown in the following Table I.

The water solubility and color subsequent to heating at 240° C. for 8hours of certain of the polyoxyalkylenes shown in the above examples isshown in Table II.

                  TABLE I                                                         ______________________________________                                        Heat Stability of Polyoxyalkylene at 240° C.                                   Acid used to                                                                  Neutralize                                                                             % Residue after Heating                                      Example No.                                                                             Catalyst   4 Hours  8 Hours 24 Hours                                ______________________________________                                        1         Salicylic  83.8     75.9    49.6                                    2         Salicylic  87.9     78.2    56.8                                    3         None       58.5     33.6    14.1                                    ______________________________________                                    

                  TABLE II                                                        ______________________________________                                        Water solubility and color of polyoxyalkylene heated at                       240° C. for 8 hours.                                                                           Estimated Water                                                               Solubility (%)                                        Example No. Gardner Color                                                                             Weight                                                ______________________________________                                        4           16          100                                                   5           11          100                                                   6           18          80                                                    7           18          50                                                    8           18          80                                                    ______________________________________                                    

EXAMPLE 13 (Control--forming no part of this invention)

A flexible polyurethane foam was prepared by mixing the followingingredients in a plastic container using an electric stirrer. A graftcopolymer dispersion in a polyol having a hydroxyl number of 26 and avinyl polymer content of 20 percent by weight was prepared by the insitu polymerization of a mixture of styrene and acrylonitrile in apolyol. Said polyol is prepared by the sequential addition of a mixtureof propylene oxide, allyl glycidyl ether, and ethylene oxide to glycerolas an initiator. Said graft copolymer dispersion 200 parts by weight,water 6 milliliters, triethylene diamine 1.4 milliliters, and anoxyalkylated silicon based surfactant sold under the trade designationDC-5043 by the Dow Corning Corporation in the amount of 4 milliliterswere added to said container. The mixture was stirred for 30 seconds andthen allowed to stand 15 seconds to promote deairation. Next, an 80/20by weight mixture of toluene diisocyanate and polymethylene polyphenylisocyanate, the toluene diisocyanate being an 80/20 by weight mixturerespectively of 2,4-, 2,6-toluene diisocyanate, 75.6 grams were addedand the mixture stirred an additional 5 seconds after wich 160 grams ofthe mixture were transferred to an 83 ounce paper container in whichfoaming took place. The foam reached the top of the cup in 66 seconds, atotal foam height of 209 millimeters and a total foam weight of 152.9grams was obtained. The foam showed essentially no shrinkage, a smoothskin, and a light yellow color.

EXAMPLE 14

Example 13 is repeated except that the graft copolymer dispersion in apolyol utilized in the preparation of the foam was modified to include0.25 parts per 100 parts of dispersion of potassium salicylate. Uponfoaming, the mixture reached the top of the paper cup in 61 seconds andachieved a total foam height of 215 millimeters. The total foam weightwas 153 grams. It was noted that the foam exhibited some shrinkage ofthe top portion of the foam, in addition, the foam appeared pock-markedat the top and had a light orange color. Upon exposing the inner portionof the foamed material by sawing through the central portion of thefoamed material, it was noted that the foam exhibited some unevenness ofthe size of the pores which generally indicates that the reactionproceeded at too fast a rate.

EXAMPLE 15 (Control--forming no part of this invention)

A rigid polyurethane composition was prepared by blending in a cleancontainer 103 grams of a polyoxypropylene initiated using glycerolhaving an average molecular weight of about 300 with 94 grams of the2-ethyl-hexanol adduct of an 80/20 mixture by weight respectively of2,4- and 2,6-toluene diisocyanate. The mixture was degassed forapproximately 3 minutes at a pressure of 10 millimeters of mercurcy andthen the mixture was added to 130 grams of a polyurethane prepolymerprepared by reacting 3620 grams of an 80/20 by weight mixture of 2,4-and 2,6-toluene diisocyanate with 779 grams of a blend of 3856 grams ofa polyoxypropylene adduct of glycerol having an average molecular weightof about 300 together with 429 grams of dipropylene glycol. Afterinsuring that the above ingredients are thoroughly mixed, 0.25 cc of astannous octoate catalyst, available as catalyst T-9 from M&TCorporation, is rapidly stirred into the mixture and then the mixture ispoured into a polished aluminum mold. After 75 seconds from the time thecatalyst was added, the mixture is set as indicated by hardening. After2 minutes from the time the catalyst was added, a rigid, hard, clearpolymer molding was obtained.

EXAMPLE 16

Example 15 is repeated except that the polyoxypropylene initiated withglycerol and having a molecular weight of about 300 contained 0.25 gramsof potassium salicylate per 100 grams of polyoxypropylene. Equivalentrigid urethane compositions are obtained as compared to those obtainedin Example 15.

EXAMPLE 17 (Control--forming no part of this invention)

A rigid polyurethane foam is prepared as follows: a mixture is preparedof 20 parts by weight of the 2-ethylhexanol adduct of an 80/20 mixturebyweight respectively of 2,4- and 2,6-toluene diisocyanate, 20 partswith a polyoxypropylene initiated with pentaerythritol having a hydroxylnumber of about 555, 100 parts by weight together with DABCO-33LV, 2.0parts by weight, and Dow Corning DC-193 surfactant, 1.5 parts by weight.Polymethylene polyphenyl polyisocyanate, sold under the trademark PAPIby the Upjohn Company, 136.4 parts by weight, is separately combinedwith Freon 11 in the amount of 35 parts by weight and the above twomixtures are combined and poured into a mold. Blowing of the foam takesplace as the heat of the reaction volatilizes the Freon 11. A rigid foamis produced.

EXAMPLE 18

Example 17 is repeated except that the polyoxypropylene adduct ofpentaerythritol having a hydroxyl number of about 55 contains 0.25 partsof potassium salicylate per 100 parts of polyoxypropylene. Comparablerigid foams are produced as compared with those prepared in Example 17.

While this invention has been described with reference to certainspecific embodiments, it will be recognized by those skilled in the artthat many variations are possible without departing from the scope andspirit of the invention, and it will be understood that it is intendedto cover all changes and modifications of the invention disclosed hereinfor the purposes of illustration which do not constitute departures fromthe spirit and scope of the invention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A composition of mattercomprising:at least one aliphatic or aromatic-substitutedpolyoxyalkylene wherein said aliphatic polyoxyalkylene is derived fromat least one alkylene oxide or glycidyl ether having 2 to 4 aliphaticcarbon atoms and wherein said aromatic-substituted polyoxyalkylene isderived from at least one aromatic substituted alkylene oxide orglycidyl ether having 2 to 4 aliphatic carbon atoms and an effectiveneutralizing amount of the alkali or alkaline earth metal salt of atleast one acid having the formula: ##STR2## wherein R₁ is selected fromthe group consisting of alkyl and alkenyl of up to 6 carbon atoms; R₂ isselected from the group consisting of hydroxyl, an alkyl ether residuehaving up to 4 carbon atoms, an hydroxyalkyl ether residue having up to4 carbon atoms, and an alkenoxy or oxyalkanoic acid ester residue havingup to 18 carbon atoms, and benzoyl; R₃ is individually selected from thegroup consisting of hydrogen, an alkyl ether residue having up to 4carbon atoms, an hydroxyalkyl ether residue having up to 4 carbon atoms,an alkyl or alkenyl group having up to 6 carbon atoms, halogen, andcarboxyl groups; and X is selected from the group consisting of (1)carbon and (2) carbon together with nitrogen.
 2. The composition ofclaim 1 wherein said acid is selected from the group consisting of atleast one of salicylic acid, acetylsalicylic acid, and ortho hydroxycinnamic acid and wherein said polyoxyalkylene is derived from at leastone alkylene oxide selected from the group consisting of ethylene oxide,1,2-propylene oxide, butylene oxide, and tetrahydrofuran.
 3. Thecomposition of claim 2 wherein said polyoxyalkylene compound is a block,heteric-block, or heteric copolymer comprising the residue of alkyleneunits derived from ethylene oxide and propylene oxide.
 4. Thecomposition of claim 3 wherein said polyoxyalkylene has a molecularweight of about 300 to about 12,500.
 5. The process of inhibiting theoxidation of a lubricant when exposed to heating conditions of at least200° C., said lubricant comprising an aliphatic polyoxyalkylene oraromatic-substituted polyoxyalkylene wherein said aliphaticpolyoxyalkylene is derived from at least one alkylene oxide or glycidylether having 2 to 4 aliphatic carbon atoms and wherein saidaromatic-substituted polyoxyalkylene is derived from at least onearomatic substituted alkylene oxide or glycidyl ether having 2 to 4aliphatic carbon atoms, said process comprising maintaining in admixturewith said polyoxyalkylene compound, an effective oxidation-inhibitingamount of the alkali or alkaline earth metal salt of at least one acidhaving the formula: ##STR3## wherein R₁ is selected from the groupconsisting of alkyl and alkenyl of up to 6 carbon atoms; R₂ is selectedfrom the group consisting of hydroxyl, an alkyl ether residue having upto 4 carbon atoms, an hydroxyalkyl ether residue having up to 4 carbonatoms, and an alkenoxy or oxyalkanoic acid ester residue having up to 18carbon atoms, and benzoyl; R₃ is individually selected from the groupconsisting of hydrogen, an alkyl ether residue having up to 4 carbonatoms, an hydroxyalkyl ether residue having up to 4 carbon atoms, alkylor alkenyl groups of up to 6 carbon atoms, halogen, and carboxyl groups;and X is selected from the group consisting of (1) carbon and (2) carbontogether with nitrogen.
 6. The process of claim 5 wherein said acid isselected from the group consisting of at least one of salicylic acid,acetylsalicylic acid, and ortho hydroxy cinnamic acid and wherein saidpolyoxyalkylene is derived from at least one alkylene oxide selectedfrom the group consisting of ethylene oxide, 1,2-propylene oxide,butylene oxide, and tetrahydrofuran.
 7. The process of claim 6 whereinsaid polyoxyalkylene lubricant comprises a block, heteric orheteric-block copolymer comprising the residues of alkylene unitsderived from ethylene oxide and propylene oxide.
 8. The process of claim7 wherein said polyoxyalkylene lubricant has a molecular weight of about300 to about 12,500.
 9. A lubricated synthetic yarn comprising asynthetic yarn and coated thereon a fiber lubricant comprising apolyoxyalkylene lubricant compound and an effective oxidation-inhibitingamount of the alkali or alkaline earth metal salt of at least one acidhaving the formula: ##STR4## wherein R₁ is selected from the groupconsisting of alkyl and alkenyl of up to 6 carbon atoms; R₂ is selectedfrom the group consisting of hydroxyl, an alkyl ether residue having upto 4 carbon atoms, an hydroxyalkyl ether residue having up to 4 carbonatoms, an alkenoxy or oxyalkanoic acid ester residue having up to 18carbon atoms, and benzoyl; R₃ is individually selected from the groupconsisting of hydrogen, an alkyl ether residue having up to 4 carbonatoms, an hydroxyalkyl ether residue having up to 4 carbon atoms, alkylor alkenyl groups having up to 6 carbon atoms, halogen, and carboxylgroups; and X is selected from the group consisting of (1) carbon and(2) carbon together with nitrogen.
 10. The lubricated synthetic yarn ofclaim 9 wherein said yarn is a polyester of nylon yarn, said acid isselected from the group consisting of at least one of salicylic acid,acetylsalicylic acid, and ortho hydroxy cinnamic acid, and wherein saidpolyoxyalkylene is derived from at least one alkylene oxide selectedfrom the group consisting of ethylene oxide, 1,2-propylene oxide,butylene oxide, and tetrahydrofuran.
 11. The lubricated yarn of claim 10wherein said polyoxyalkylene compound comprises a block, heteric, orheteric-block copolymer comprising the residues of alkylene unitsderived from ethylene oxide and propylene oxide and said yarn is apolyester yarn.
 12. The polyester yarn of claim 10 wherein saidpolyoxyalkylene lubricant compound has a molecular weight of about 300to about 12,500.